Control device



April 23, 1957 R. N. BOOTH CONTROL mzvxcs Filed Sept. 29, 1955 IN V ENTOR.

RUSSELL N BOOTH ATTORNEY United States Patent 14 Claims. (Cl. 200--83)This invention relates to control devices and more particularly to adevice providing for the actuation of a pair of control elementsutilizing independent control point adjustments with only a singlecondition sensing means.

One embodiment of my invention utilizes the independent control pointadjustment for a combination fan and limit control with but a singlesensing element and power head. This, therefore, will mean a combinationfan and limit control that is more economical to manufacture.

Therefore, an object of my invention is to provice a control device inwhich there is independent adjustment of the control point actuation oftwo control elements actuated by a single power head and conditionsensing element.

Another object of my invention is to provide a combination fan and limitcontrol with independent control point adjustment and one sensingelement.

Further objects of my invention will become evident upon inspection ofthe following drawings, specification and claims.

Figure l is a diagrammatic perspective illustrating the principle of myinvention.

Figure 2 is a plan view of one embodiment of my invention.

Figure 3 is an elevation of the embodiment of Figure 2 taken along line3-3 of Figure 2.

Referring now to Figure 1, a floating lever is actuated by a conditionsensing means 11 and is engaged by the end 14 of shaft 15 which isconnected thereto. Condition sensing means 11 is shown as a power head16 in which a diaphragm is actuated by a sensing fluid through capillarytube 18. Power head 16 is fixed in a frame indicated diagrammatically as20. Expansion or contractionof the diaphragm due to a condition changewill cause axial movement of the shaft 15.

A compression spring 22 acts between frame 29 and lever 10 and engageslever 10 on a line parallel to but displaced from the axis of shaft 15.A pair of independently adjustable abutments 25 and 26 threadedly engageframe 20 and are positioned for cooperation with lever ltl. A pair ofabutments 28 and 29 are fixed by frame 21; and are positioned forcooperation with lever 10. Another pair of adjustable abutments 30 and31 threadedly engage frame 20 and are positioned for cooperation withlever 10.

With the lever 10 positioned as shown and biased by spring means 22 intoengagement with shaft 15' and abutments 28 and 29, a change in conditionto cause e7; tasien of the diaphragm will cause upward movement of shaft15 against the bias of spring means 22 pivoting lever it? about the axisformed by abutments 23 and 29. This movement will continue until lever10 has pivoted sufficiently to engage the abutment 26 which is adjustedcloser to lever ill than is abutment 25 whereupon continued movement ofshaft 15 will cause movement of lever 10 about the pivotal axisestablished by abutments 28 and 26. Further pivoting about the axisformed by abutments 28 and 26 will cause lever 10 to move away fromabutment 29 and toward 2,790,044 Patented Apr. 23, 1957 abutment 25.After engagement of abutment 25 by lever 10 the pivotal axis of lever 10will have shifted to that formed by abutments 25 and 26. Furtherpivoting about the axis formed by abutments 25 and 26 will cause lever10 to move away from abutment 28. Abutments 28 and 29 may be switchcontacts and the portion of lever 10 engaged thereby may be cooperatingcontacts which may be insulated from the lever 10 if desired.

In case of an undesirably low condition value or a collapse of powerhead 11 spring means 22 will move lever 10 downward about abutments 28and 29 until lever 10 engages abutment 30 which is adjusted closer tolever 16 than is abutment 31 at which point lever 10 will pivot aboutabutments 30 and 28 disengaging lever 10 from abutment 29. Furtherpivoting about the axis formed by abutments 30 and 28 will cause lever10 to engage abutment 31. After engagement of abutment 31 the pivotalaxis of lever 10 will have shifted to that formed by abutments 30 and31. Further pivoting of lever 10 about the axis formed by abutments 30and 31 will cause lever 10 to pivot away from abutment 28. Theundesirably low condition value at which abutments 28 and 29 will bedisengaged from lever 10 can be independently adjusted by positioning ofabutments 30 and 31.

The principle of my invention will operate for any interchange ofpositions between abutments 28, 29, and adjustable abutments 25, 26 andpower head 16 and adjustable abutments 30, 31. As can be seen from theabove discussion and Figure 1, the point 14 of application of the powerhead 11 to lever 10, engagement of abutment 26 with lever 1t? andengagement of abutment 29 with lever 19 he substantially in a line andlikewise point 14, engagement of abutment 25 and engagement of abutment23 with lever 10 lie substantially in a line. Theoretically, the anglebetween these lines can be anything except 0 or 180.

With 14, 26, and 29 in alignment and 14, 25, and 28 in alignment theadjustment of 26 will have no effect on condition value separating lever10 from 28 and adjustment of 25 will have no effect on condition valueseparating lever 10 from 29.

The elements forming the lower control point adjustment can be out ofline without affecting the independent control point adjustment if theelements forming the higher control point adjustment are in line. Thus26 can be displaced from alignment with 14 and 29 without its adjustmentaffecting condition value at which lever 10 separates from abutment 28.The three points of the high side of course do not have to be in linefor the instrument to function but then there will be interdependence ofsettings.

In the general use of domestic forced warm air furnaces it is desirableto provide thermostatic control of both the fan motor and burnercircuits, in which the fan switch makes and the high limit switch breakson temperature rise.

An embodiment of my invention for use as a combination fan and limitcontrol is shown in Figures 2 and 3 in which the floating lever isengaged by power head 116 at the end 114 of a shaft 115. Diaphragm 117and casing 119 of power head 116 define a chamber 121 which receivessensing fluid through capillary tube 118 from a temperature sensing bulb(not shown). Casing 119 is attached to frame 120 and positions powerhead 116 with respect to frame 120. Diaphragm 117 engages a pad 123 onshaft 115 and upon a temperature change the resultant volume change inchamber 121 will cause movement of shaft 115 and resulting movement oflever 110. A spring 122 is positioned at one end by an extension 124 offrame 120. The other end of spring 122 cooperates with lever 110 andbiasesit against. shaft 115 and power head 116. A pair of;screws 125 and126 threadedly engage extension 124 of frame 120. and are positioned forcooperation with lever 110. Switches 128 and 129 are positioned by frame120 such that their actuator plungers are positioned for cooperationwith lever 110. Plunger 132 of switch 128 may be seen in Figure 3. Lever11%, positioned as shown, is biased by spring means 122 into engagementwith shaft 115 and screw abutments 125 and 126. A rise in temperaturewill cause an increase of volume in chamber 121 with a resultantdeflection to the left as seen in Figure 3 of diaphragm 117 and shaft115. This will cause counter clockwise rotation of lever 110 about screwabutments 125 and 126 causing actuation of switches 128 and 129. Theposition of screw abutments 125 and 126 can be adjusted by levers 133and 134 which cooperate with indicia of temperature 135 and 136 onextension 124 of frame 120. The position of screw 125 will determine thetemperature at which switch 128 will be actuated and the position ofscrew 126 will determine the position at which switch 129 will beactuated.

Adjustable screw 130 is provided as a fail'safe feature. It diaphragm117 ruptures, spring 122 will bias lover .110 about the actuators of:switches 128 and 129 until lever 110 engages screw 130; at this pointlever 110 will pivot about screw 130 causing lever 110 to leave actuator.132 of switch 128 and as switch 128 is the high limit control,actuation of it will turn the system off.

In the embodiment shown in Figures 2 and 3 the point. 114, screw 126 andthe actuator of switch 129 are in alignment, and the point 114, screw125 and the actuator 132 Of switch 128 are in alignment. Therefore,levers 133 and 134 may be adjusted to independently select thetemperatures at which the limit and fan switches will be actuated.

The operation of the embodiment of the invention shown in Figures 2 and3 differs from that of Figure l in that the switches 128 and 129 have aninherent overtravcl and their plungers may be moved inwardly for somedistance after the switch has been operated. Operation of the switchesat the control points selected by levers 133 and 134 is nevertheless thesame as described in connection with Figure 1.

In the broad usage of my invention various componcnts may be varied,changed or substituted for without changing the spirit of my invention.For example, the spring bias means is shown as one spring in a specificlocation. Obviously, one or more spring means may be used in any of manylocations. Also if instead of abutments or switches for control elements28 and 29 other types of actuators for control elements such aspotentiometers are used the device would function by pivoting about theaxis formed by screws 25 and 26. The actuation of the control. elementsubstituted for abutment 23 would be controlled by the position of screw25, and the actuation of the control element substituted for abutment 29would be controlled by the position of screw 26.

I do not intend to limit my invention to the embodiments shown but onlyas defined in the appended claims.

I claim as my invention:

1. In a condition responsive device a pair of control elements,condition sensing means, lever means, spring means normally biasing saidlever means into c00peration with said control elements and saidcondition sensing means, a pair of abutments each being adapted toengage said lever means to determine the condition value at which saidlever means pivots about one of said abutments actuating one of saidcontrol elements.

2. In a condition responsive device a pair of control elements,condition sensing means, lever means, spring means normally biasing saidlever means into cooperation with said control elements and saidcondition sensing means, a pair of abutments each being adapted toengage said lever means to determine the condition value at which saidlever means pivots about one of said abutments actuating one of saidcontrol elements, and means for adjustably positioning each of saidabutments to dctermine the point of actuation of each of said controlelements.

3. In a condition responsive device a pair of control elements,condition sensing means, lever means, spring means normally biasing saidlever means into cooperation with said control elements and saidcondition sensing means, a pair of abutments each being adapted toengage said lever means to determine the condition value at which saidlever means pivots about one of said abutments actuating one of saidcontrol elements, said one of said abutments and said one of saidcontrol elements actuated by pivotal movement of said lever about saidone of said abutments and the point of cooperation of said conditionsensing means on said lever means being substantially in a straightline.

4. In a condition responsive device a pair of control elements,condition sensing means, lever means, spring means normally biasing saidlever means into cooperation with said control elements and saidcondition sensing means, a pair of abutments each being adapted toengage said lever means to determine the condition value at which saidlever means pivots about one of said abutments actuating one of saidcontrol elements, for each of said abutments adjusting means andcooperating indicia of condition value indicating the condition value atwhich each of said control means will be actuated.

5. in a condition responsive device, lever means, first and secondabutments engaging said lever means at spaced points to establish a.pivotal axis for said lever means, condition responsive means engagingsaid lever means at a point removed from said pivotal axis and adaptedto pivotally move said lever means on condition change, a plurality ofcontrol elements disposed to be actuated by pivotal movement of saidlever means, and means for adjustably positioning each of saidabutments.

6. In. a condition responsive device, lever means, first and secondabutments engaging said lever means at spaced points to establish apivotal axis for said lever means, condition responsive means engagingsaid lever means at a point removed from said pivotal axis and adaptedto pivotally move said lever means on condition change, a controlelement disposed to be actuated by pivotal movement of said lever means,and means for adjustably positioning each of said abutments.

7. In a condition responsive device, lever means, first and secondabutments engaging said lever means at spaced points to establish apivotal axis for said lever means, condition responsive means engagingsaid lever means at a point removed from said pivotal axis and adaptedto pivotaliy move said lever means on condition change, two controlelements disposed to be actuated by pivotal movement of said levermeans, each of said elements being disposed substantially in line withsaid condition responsive means and one of said abutments, and means foradjustubly positioning each of said nbutments.

8. in a condition responsive device, a frame, first and second spacedabutments in said frame, lever means engaging said abutments, conditionresponsive means engaging said lever means and adapted on conditionchange to pivotally move said lever means about the axis estab lished bysaid abutments, a first control means actuated by a point on said leverin line with said first abutment, a second contro 1ElnS actuated by apoint on said lever in line with suit. second abutment, adjusting meansfor each of said abutments carried by said frame, and c0- operatingindicia of condition value on said frame and on said adjusting meansindicating the condition value at which each of said control means willbe actuated.

9. in a condition responsive device lever means, first and secondab'ltmcnts positioned for cooperation with said lever means. conditionsensing means cooperating with said lever means at a point removed fromsaid abutme a spring means cooperating with said lever means oppo ngsaid condition sensing means, a control element actuated by pivotalmovement of said lever, and the point of cooperation on said lever ofsaid control element, one

of said abutments and said condition sensing means being substantiallyin a straight line.

10. In a condition responsive device lever means, first and secondabutments positioned for cooperation with said lever means, conditionsensing means cooperating with said lever means at a point removed fromsaid abutments, a spring means cooperating with said lever meansopposing said condition sensing means, first and second control elementsactuated by pivotal movement of said lever, and the point of cooperationon said lever of one of said control elements, one of said abuttneitsand condition sensing means being substantially in a stra gt line andmeans for adjustably positioning each of said abutments to determine thepoint of actuation of each of said control elements.

11. In a condition responsive device lever means, a pair of abutmentspositioned for cooperation with said lever means, condition responsivemeans engaging said lever means at a point removed from said abutmentand adapted to pivotally move said lever means on condition change abouteither of said abutments, a plurality of control elements disposed to beactuated by pivotal movement of said lever means, each of said elementsbeing actuated upon pivotal movement of said lever means about one ofsaid abutments, and means for adjustably positioning each of saidabutments to determine the point of actuation of each of said controlelements.

12. In a condition responsive device a control element, conditionsensing means, lever means, spring means normally biasing said levermeans into cooperation with said control element and said conditionsensing means, a pair of abutments each being adapted to engage saidlever means to determine the condition value at which said lever meanspivots about said abutments actuating said control elements.

13. In a condition responsive device a control element, conditionsensing means, lever means, spring means normally biasing said levermeans into cooperation with said control element and said conditionsensing means, a pair of abutm nts each being adapted to engage saidlever means to determine the condition value at which said lever meanspivots about said abutments actuating said controi elements, and meansfor adjustably positioning each of said abutments to calibrate anddetermine the point of actuation of said control element.

14. in a control device, a frame, a lever in the form of plate; co; ionresponsive device on said frame having an output shaft engaging one sideof said plate, said shaft moving normal to said plate upon a change incondition; first and second abutments adjustable in said frame andadapted to engage said plate at spaced points equal distance from saidshaft, said abutments being adjustable normal to said plate; cooperatingindices of condition value on said frame and said abutments; first andsecond elements to be controlled, said elements engaging said plate andbeing displaced from said shaft and said abutments, the points ofengagement of said shaft, said first abutment and said first elementbeing in a first straight line, the points of engagement of said shaft,said second abutment, and said second element being in a second straightline; and spring means acting between said frame and said plate biasingsaid plate about said shaft in a direction to engage both of saidabutments.

References Klited in the file of this patent UNITED STATES PATENTS2,355,975 Henrici Aug. 15, 1944 2,437,846 Yeida Mar. 16, 1948 2,578,340De Lancey Dec. 11, 1951 2,720,563 Williams Oct. 11, 1955

